A High Energy Density Self-supported and Bendable Organic Electrode for Redox Supercapacitors with a Wide Voltage Window

Redox-active organic electrode materials are highly desirable in realizing next-generation all-in-one bendable electronic systems. Herein, a novel flexible supercapacitors (SCs) electrode is fabricated from poly(anthraquinonyl sulfide) (PAQS) and single-walled carbon nanotubes (SWCNTs) suspension by a simple vacuum filtration and named as PAQS-SWCNTs. The PAQS-SWCNTs electrode offered an initial capacitance of 223 F-g⁻¹ and outstanding capacitance retention up to 78.4% after 3 × 10⁴ charge-discharge cycles at 0.5 A-g⁻¹ current density. In a high potential range (0-3 V) and aprotic electrolyte, the PAQS-SWCNTs electrodes in coin cell exhibited an outstanding energy density of 69 Wh-kg⁻¹ at a power density of 90.6 W-kg⁻¹, whereas in the fabricated flexible SCs it retained 63.2 Wh-kg⁻¹. The PAQS-SWCNTs electrodes also showed extraordinary performance at a higher current density (20 A-g⁻¹) and maintained a specific capacitance of 55 and 47 F-g⁻¹ for coin and flexible SCs, respectively. Moreover, the flexible SC is further verified to be able to illuminate up multiple LEDs. These futuristic findings showed that the SCs assembled with flexible PAQS-SWCNTs electrodes have potential application in energy-storage devices and make them highly appealing for future redox supercapacitors.